ustream-polarssl.c

   1 /*
   2  * ustream-ssl - library for SSL over ustream
   3  *
   4  * Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
   5  *
   6  * Permission to use, copy, modify, and/or distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include <sys/types.h>
  20 #include <fcntl.h>
  21 #include <unistd.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24
  25 #include "ustream-ssl.h"
  26 #include "ustream-internal.h"
  27
  28 static int urandom_fd = -1;
  29
  30 static int s_ustream_read(void *ctx, unsigned char *buf, size_t len)
  31 {
  32         struct ustream *s = ctx;
  33         char *sbuf;
  34         int slen;
  35
  36         if (s->eof)
  37                 return 0;
  38
  39         sbuf = ustream_get_read_buf(s, &slen);
  40         if (slen > len)
  41                 slen = len;
  42
  43         if (!slen)
  44                 return POLARSSL_ERR_NET_WANT_READ;
  45
  46         memcpy(buf, sbuf, slen);
  47         ustream_consume(s, slen);
  48
  49         return slen;
  50 }
  51
  52 static int s_ustream_write(void *ctx, const unsigned char *buf, size_t len)
  53 {
  54         struct ustream *s = ctx;
  55         int ret;
  56
  57         ret = ustream_write(s, (const char *) buf, len, false);
  58         if (ret < 0 || s->write_error)
  59                 return POLARSSL_ERR_NET_SEND_FAILED;
  60
  61         return ret;
  62 }
  63
  64 __hidden void ustream_set_io(struct ustream_ssl_ctx *ctx, void *ssl, struct ustream *conn)
  65 {
  66         ssl_set_bio(ssl, s_ustream_read, conn, s_ustream_write, conn);
  67 }
  68
  69 static bool urandom_init(void)
  70 {
  71         if (urandom_fd > -1)
  72                 return true;
  73
  74         urandom_fd = open("/dev/urandom", O_RDONLY);
  75         if (urandom_fd < 0)
  76                 return false;
  77
  78         return true;
  79 }
  80
  81 static int _urandom(void *ctx, unsigned char *out, size_t len)
  82 {
  83         if (read(urandom_fd, out, len) < 0)
  84                 return POLARSSL_ERR_ENTROPY_SOURCE_FAILED;
  85
  86         return 0;
  87 }
  88
  89 __hidden struct ustream_ssl_ctx *
  90 __ustream_ssl_context_new(bool server)
  91 {
  92         struct ustream_ssl_ctx *ctx;
  93
  94         if (!urandom_init())
  95                 return NULL;
  96
  97         ctx = calloc(1, sizeof(*ctx));
  98         if (!ctx)
  99                 return NULL;
 100
 101         ctx->server = server;
 102         pk_init(&ctx->key);
 103
 104         return ctx;
 105 }
 106
 107 __hidden int __ustream_ssl_add_ca_crt_file(struct ustream_ssl_ctx *ctx, const char *file)
 108 {
 109         int ret;
 110
 111         ret = x509_crt_parse_file(&ctx->ca_cert, file);
 112         if (ret)
 113                 return -1;
 114
 115         return 0;
 116 }
 117
 118 __hidden int __ustream_ssl_set_crt_file(struct ustream_ssl_ctx *ctx, const char *file)
 119 {
 120         int ret;
 121
 122         ret = x509_crt_parse_file(&ctx->cert, file);
 123         if (ret)
 124                 return -1;
 125
 126         return 0;
 127 }
 128
 129 __hidden int __ustream_ssl_set_key_file(struct ustream_ssl_ctx *ctx, const char *file)
 130 {
 131         int ret;
 132
 133         ret = pk_parse_keyfile(&ctx->key, file, NULL);
 134         if (ret)
 135                 return -1;
 136
 137         return 0;
 138 }
 139
 140 __hidden void __ustream_ssl_context_free(struct ustream_ssl_ctx *ctx)
 141 {
 142         pk_free(&ctx->key);
 143         x509_crt_free(&ctx->ca_cert);
 144         x509_crt_free(&ctx->cert);
 145         free(ctx);
 146 }
 147
 148 static void ustream_ssl_error(struct ustream_ssl *us, int ret)
 149 {
 150         us->error = ret;
 151         uloop_timeout_set(&us->error_timer, 0);
 152 }
 153
 154 static bool ssl_do_wait(int ret)
 155 {
 156         switch(ret) {
 157         case POLARSSL_ERR_NET_WANT_READ:
 158         case POLARSSL_ERR_NET_WANT_WRITE:
 159                 return true;
 160         default:
 161                 return false;
 162         }
 163 }
 164
 165 static void ustream_ssl_verify_cert(struct ustream_ssl *us)
 166 {
 167         void *ssl = us->ssl;
 168         const char *msg = NULL;
 169         bool cn_mismatch;
 170         int r;
 171
 172         r = ssl_get_verify_result(ssl);
 173         cn_mismatch = r & BADCERT_CN_MISMATCH;
 174         r &= ~BADCERT_CN_MISMATCH;
 175
 176         if (r & BADCERT_EXPIRED)
 177                 msg = "certificate has expired";
 178         else if (r & BADCERT_REVOKED)
 179                 msg = "certificate has been revoked";
 180         else if (r & BADCERT_NOT_TRUSTED)
 181                 msg = "certificate is self-signed or not signed by a trusted CA";
 182         else
 183                 msg = "unknown error";
 184
 185         if (r) {
 186                 if (us->notify_verify_error)
 187                         us->notify_verify_error(us, r, msg);
 188                 return;
 189         }
 190
 191         if (!cn_mismatch)
 192                 us->valid_cn = true;
 193 }
 194
 195 __hidden enum ssl_conn_status __ustream_ssl_connect(struct ustream_ssl *us)
 196 {
 197         void *ssl = us->ssl;
 198         int r;
 199
 200         r = ssl_handshake(ssl);
 201         if (r == 0) {
 202                 ustream_ssl_verify_cert(us);
 203                 return U_SSL_OK;
 204         }
 205
 206         if (ssl_do_wait(r))
 207                 return U_SSL_PENDING;
 208
 209         ustream_ssl_error(us, r);
 210         return U_SSL_ERROR;
 211 }
 212
 213 __hidden int __ustream_ssl_write(struct ustream_ssl *us, const char *buf, int len)
 214 {
 215         void *ssl = us->ssl;
 216         int done = 0, ret = 0;
 217
 218         while (done != len) {
 219                 ret = ssl_write(ssl, (const unsigned char *) buf + done, len - done);
 220
 221                 if (ret < 0) {
 222                         if (ssl_do_wait(ret))
 223                                 return done;
 224
 225                         ustream_ssl_error(us, ret);
 226                         return -1;
 227                 }
 228
 229                 done += ret;
 230         }
 231
 232         return done;
 233 }
 234
 235 __hidden int __ustream_ssl_read(struct ustream_ssl *us, char *buf, int len)
 236 {
 237         int ret = ssl_read(us->ssl, (unsigned char *) buf, len);
 238
 239         if (ret < 0) {
 240                 if (ssl_do_wait(ret))
 241                         return U_SSL_PENDING;
 242
 243                 ustream_ssl_error(us, ret);
 244                 return U_SSL_ERROR;
 245         }
 246
 247         return ret;
 248 }
 249
 250 static const int default_ciphersuites[] =
 251 {
 252 #if defined(POLARSSL_AES_C)
 253 #if defined(POLARSSL_SHA2_C)
 254     TLS_RSA_WITH_AES_256_CBC_SHA256,
 255 #endif /* POLARSSL_SHA2_C */
 256 #if defined(POLARSSL_GCM_C) && defined(POLARSSL_SHA4_C)
 257     TLS_RSA_WITH_AES_256_GCM_SHA384,
 258 #endif /* POLARSSL_SHA2_C */
 259     TLS_RSA_WITH_AES_256_CBC_SHA,
 260 #endif
 261 #if defined(POLARSSL_CAMELLIA_C)
 262 #if defined(POLARSSL_SHA2_C)
 263     TLS_RSA_WITH_CAMELLIA_256_CBC_SHA256,
 264 #endif /* POLARSSL_SHA2_C */
 265     TLS_RSA_WITH_CAMELLIA_256_CBC_SHA,
 266 #endif
 267 #if defined(POLARSSL_AES_C)
 268 #if defined(POLARSSL_SHA2_C)
 269     TLS_RSA_WITH_AES_128_CBC_SHA256,
 270 #endif /* POLARSSL_SHA2_C */
 271 #if defined(POLARSSL_GCM_C) && defined(POLARSSL_SHA2_C)
 272     TLS_RSA_WITH_AES_128_GCM_SHA256,
 273 #endif /* POLARSSL_SHA2_C */
 274     TLS_RSA_WITH_AES_128_CBC_SHA,
 275 #endif
 276 #if defined(POLARSSL_CAMELLIA_C)
 277 #if defined(POLARSSL_SHA2_C)
 278     TLS_RSA_WITH_CAMELLIA_128_CBC_SHA256,
 279 #endif /* POLARSSL_SHA2_C */
 280     TLS_RSA_WITH_CAMELLIA_128_CBC_SHA,
 281 #endif
 282 #if defined(POLARSSL_DES_C)
 283     TLS_RSA_WITH_3DES_EDE_CBC_SHA,
 284 #endif
 285     0
 286 };
 287
 288 __hidden void *__ustream_ssl_session_new(struct ustream_ssl_ctx *ctx)
 289 {
 290         ssl_context *ssl;
 291         int auth;
 292         int ep;
 293
 294         ssl = calloc(1, sizeof(ssl_context));
 295         if (!ssl)
 296                 return NULL;
 297
 298         if (ssl_init(ssl)) {
 299                 free(ssl);
 300                 return NULL;
 301         }
 302
 303         if (ctx->server) {
 304                 ep = SSL_IS_SERVER;
 305                 auth = SSL_VERIFY_NONE;
 306         } else {
 307                 ep = SSL_IS_CLIENT;
 308                 auth = SSL_VERIFY_OPTIONAL;
 309         }
 310
 311         ssl_set_ciphersuites(ssl, default_ciphersuites);
 312         ssl_set_endpoint(ssl, ep);
 313         ssl_set_authmode(ssl, auth);
 314         ssl_set_rng(ssl, _urandom, NULL);
 315
 316         if (ctx->server) {
 317                 if (ctx->cert.next)
 318                         ssl_set_ca_chain(ssl, ctx->cert.next, NULL, NULL);
 319                 ssl_set_own_cert(ssl, &ctx->cert, &ctx->key);
 320         } else {
 321                 ssl_set_ca_chain(ssl, &ctx->ca_cert, NULL, NULL);
 322         }
 323
 324         ssl_session_reset(ssl);
 325
 326         return ssl;
 327 }
 328
 329 __hidden void __ustream_ssl_session_free(void *ssl)
 330 {
 331         ssl_free(ssl);
 332         free(ssl);
 333 }
 334
 335 __hidden void __ustream_ssl_update_peer_cn(struct ustream_ssl *us)
 336 {
 337         struct ustream_ssl_ctx *ctx = us->ctx;
 338
 339         ssl_set_ca_chain(us->ssl, &ctx->ca_cert, NULL, us->peer_cn);
 340 }